1. Field of the Invention
The present invention relates to a multilayer ceramic capacitor and a method of manufacturing the same, and more particularly, a high capacitance multilayer ceramic capacitor having excellent reliability and a method of manufacturing the same.
2. Description of the Related Art
Generally, electronic components using a ceramic material, such as a capacitor, an inductor, a piezoelectric element, a varistor, a thermistor, or the like, include a ceramic body made of a ceramic material, internal electrodes formed in the ceramic body, and external electrodes mounted on external surfaces of the ceramic body so as to be connected to the internal electrodes.
Among ceramic electronic components, a multilayer ceramic capacitor includes a plurality of stacked dielectric layers, internal electrodes disposed to face each other, having the dielectric layer therebetween, and external electrodes electrically connected to the internal electrodes.
Multilayer ceramic capacitors have been widely used as components in mobile communications devices such as laptop computers, personal digital assistants (PDAs), mobile phones, and the like, due to advantages thereof such as a small size, high capacitance, ease of mounting, or the like.
Recently, as electronic products have been miniaturized and multi-functionalized, chip components have also tended to be miniaturized and multi-functionalized. As a result, there is a need to miniaturize multilayer ceramic capacitors and increase the capacity thereof.
In order to increase the capacitance of multilayer ceramic capacitors, methods of thinning the dielectric layers thereof, stacking the thinned dielectric layers, and improving coverage of the internal electrodes have been considered. In addition, a method for improving an area of the internal electrodes overlapped for forming capacitance has been considered.
In general, multilayer ceramic capacitors have been manufactured as follows. First, a ceramic green sheet is prepared, and a conductive paste is printed on the ceramic green sheet to form the internal electrode. The ceramic green sheets having the internal electrodes formed thereon are stacked in an amount of several tens of layers to several hundreds of layers to fabricate a green ceramic multilayer body. Thereafter, the green ceramic multilayer body is compressed under conditions of high temperature and high pressure to fabricate a hard green ceramic multilayer body, and a cutting process is performed on the ceramic multilayer body to fabricate a green chip. Next, the green chip is calcined and sintered, and the external electrodes are formed thereon to complete the multilayer ceramic capacitor.
In the case of manufacturing a multilayer ceramic capacitor through the above-described manufacturing method, since it is difficult to significantly decrease a margin part region of the dielectric layer on which the internal electrode is not formed, there is a limitation in increasing the overlap area of the internal electrodes. In addition, since the margin part of an edge of the multilayer ceramic capacitor is formed to be thicker than margin parts in other regions, it is not easy to remove carbon therefrom at the time of calcining and sintering.
In order to solve the above-described limitations, a method, in which the margin part region on which the internal electrode is not formed is formed in the previously manufactured ceramic multilayer body, has been considered, but the method has a defect in that the manufactured ceramic multilayer body has decreased moisture-resistance characteristics and is vulnerable to impacts due to a non-compression area between the ceramic multilayer body and the margin part.
The related art document below variably controls an average grain size of dielectric grains configuring the capacitance part and an average grain size of dielectric grains configuring the specific capacitance part, but does not solve the above-described defects.